An international team of scientists was able to transplant climate-resistant corals to another territory. They survived and did not fade.
The researchers explained that in 2015, nearly half of Hawaii’s coral reefs suffered the worst bleaching to date. Coral bleaching occurs when warmer-than-normal ocean temperatures cause corals to expel algae, which usually live inside them and which corals rely on for food.
Bleaching is alarming, but sometimes corals can recover while others do not bleach at all. In a new study published in the journal Proceedings of the National Academy of Sciences, scientists led by Katie Barott of the University of Pennsylvania found that these resilient corals can grow even when transplanted into a different environment and subjected to additional heat stress. The findings give hope that hardy corals can serve as a population base for reef restoration in the future.
“The main thing we were really interested in was trying to experimentally test whether coral that appears to be resistant to climate change could be taken and used as a seedbed to propagate and plant on another reef that might be degrading,” the researchers noted. “The most interesting thing is that we did not see any difference in the response of corals to bleaching after transplant.”
Massive incidents of coral bleaching are occurring with increasing frequency, raising fears that corals will become victims of climate change in the near future. However, Barott and colleagues are studying corals that resist bleaching in order to buy corals more time to withstand warming and acidic ocean waters.
One strategy they and others have proposed, which has already been tested in areas like the Great Barrier Reef, is coral transplantation. Researchers could transplant corals on reefs damaged by climate change or other anthropogenic influences, such as sedimentation or grounded ships, that have proven their strength and ability to survive in harsh environments.
However, for this to work, the corals need to continue to show their resilience after being moved to a new environment. In their experiment, the corals spent six months in a new location, biologists put coral samples from each site into aquariums in the laboratory and simulated another bleaching event, raising the water temperature by several days.